METHOD AND APPARATUS FOR FEEDING ENVELOPES

摘要

A method and apparatus for feeding envelopes in an envelope insertion machin e, wherein a rotatable pneumatic feeding head (40) is used to pick up an envelo pe from an envelope stack by a negative air pressure. The pneumatic feeding hea d is also used to move the envelope to a pair of take away rollers (26) so tha t the envelope picked up by the feeding head can be moved further away from th e envelope stack. It is preferred that the feeding head includes an outer cylinder (50) having a row of vacuum ports (42) and an inner cylinder (60) having a plurality of apertures (62) for air passage operatively connected t o a vacuum pump. The inner cylinder (60) is independently rotatable relative t o the outer cylinder (50) so that the negative air pressure is provided to the vacuum ports (42) when the apertures (62) of the inner cylinder (60) are aligned with the vacuum ports (42), and the negative air pressure is turned off from the vacuum ports (42) when the apertures (62) and the vacuum ports (42) are out of alignment.